Design and optimisation of an antenna array for WIMAX base stations

To increase the capacity and coverage in broadband data communication according to the IEEE 802.16e WiMAX standard, an intelligent base station antenna with beam- and nullsteering over a full circle is developed and optimised. In this paper a circular antenna array of 8 vertical dipoles with a feeding network is described, which provides m beams simultaneously in m directions for m subscribers with a full coverage of 360 around the basestation. By means of optimisation techniques it is either possible to provide a null without ambiguity in every direction, or to optimize the side lobe attenuation by calculating the amplitudes and phases of every antenna of the array. With this, detection finding or location based services are also possible.